How do I edit a PDF for free?

Open it in a free browser editor such as the one on this site, add text, drawings, signatures or form answers, then download the new file. For re-writing whole paragraphs, edit the original Word or Google Docs file and export a new PDF instead.

How do I edit a PDF on a Mac without extra software?

macOS Preview can add text boxes, shapes and a signature (Tools → Annotate). A browser editor does the same on any computer and adds form detection, real redaction and page notes.

How do I edit a PDF in Word?

Word can open a PDF and convert it into an editable document (File → Open). It works well on simple text documents and badly on forms, tables and complex layouts, so check the result carefully before saving it back to PDF.

Why is some PDF text impossible to select or edit?

It is probably a scan: a photo of the page with no text in it at all. You can still write on top, highlight and sign; to make the text itself selectable, it needs OCR (text recognition) in a dedicated app.

How to edit a PDF

Most "edit my PDF" jobs are small: fill a form, sign it, fix a date, add a note. Those take a minute in a browser. Rewriting whole paragraphs is a different job, and knowing why saves a lot of frustration.

Open the free editor

Pick the method by what you need to change

You need to…	Best approach
Fill in a form	Fill PDF form: type into its fields, or onto the lines if it's flat
Sign it	Sign PDF: draw, type or upload your signature
Add a few words, a date or an address	Add text on top of the page
Fix a typo	Whiteout the old word, type the new one on top
Hide personal data before sharing	Redact (never just a black box)
Review or give feedback	Annotate with highlights and comments
Study or summarise it	PDF notes beside each page
Rewrite paragraphs or change the layout	Edit the original source file (Word, Docs, InDesign) and export again

Why you can't just click into a PDF and retype it

PDF was designed by Adobe in 1993 as a print format: its job is to make a page look identical everywhere. So a page isn't stored as paragraphs that wrap. It is stored as drawing instructions, roughly "use this font at 11 points, move to x=72, y=640, show these glyphs". Delete a word and nothing knows it should pull the rest of the line left, let alone re-wrap the paragraph.

That is why every browser editor, this one included, works by adding to the page rather than rewriting it. Additions are safe: they go on top as new instructions or annotations and leave the original untouched.

Editing a PDF on each kind of device

Windows

Microsoft Edge's built-in PDF viewer can draw, highlight and add text; Word can convert simple PDFs to editable documents. For forms, signatures and redaction, use a browser editor.

Mac

Preview (Tools → Annotate) adds text boxes, shapes and a trackpad-drawn signature. It can't truly redact: its black boxes are annotations.

iPhone and Android

iOS Files has a Markup button for drawing and signing. On Android, Google Drive's PDF viewer can fill forms and annotate. A browser editor works the same on both, with a finger-drawn signature.

Any device, in the browser

The PDF Notepad editor runs in Chrome, Safari, Edge and Firefox on all of the above, and never uploads the file.

A checklist before you send an edited PDF

Open the downloaded copy in a different viewer from the one you edited in.
Check every form answer shows (flatten if a viewer shows blank boxes).
Try selecting text under any redaction: nothing should select.
Rename the file clearly, e.g. lease-renewal-signed-2026-09.pdf.

So a PDF page is really a stack of drawing instructions, not a sheet of words. For another process that looks simple from outside, ahaboo has a narrated explainer on how a leaf turns light into sugar.